Don't Let Electrical "smoldering" Destroy Reliability: Investigating The Mastermind Behind Ionization Discharge On Insulator Surfaces

During routine inspections of power transmission lines or maintenance of substations, veteran maintenance workers often say that if you hear a faint "buzzing" sound around dead end insulators, you should pay attention. This sound often indicates potential ionizing discharge on the dead end suspension insulators surface. While this localized discharge may seem insignificant, it's like a chronic disease, slowly eroding the foundation of the power system's safety.

Why do insulator surfaces "spark"?

This discharge phenomenon doesn't occur out of thin air; it's usually the result of a interaction between the environment and physical properties.

• A chain reaction triggered by dirt accumulation:

Insulators operating outdoors inevitably accumulate dust, salt, or industrial particles. When rain or snow arrives, these contaminants become damp and transform into a conductive layer. Current forces its way across the unevenly moist surface, instantly maximizing the local electric field, accelerating the ejection of electrons from the air, and initiating the discharge.

• Physical flaws due to material aging:

Prolonged exposure to intense sunlight, wind, rain, and snow will cause the material properties of polymer deadend insulator to deteriorate. Tiny cracks or rough pits on the surface become natural "hotspots" for charge accumulation. When the potential difference exceeds the air's tolerance limit, a faint arc of light leaps across these imperfections.

• Electrical field compression due to structural unevenness:

If the insulator itself contains extremely small air bubbles or impurities during manufacturing, or if the connections are not tight enough during installation, the electric field distribution will become congested, like traffic during rush hour. High-voltage electricity seeks a breakthrough at these stress concentration points, and ionization discharge becomes the most direct manifestation.

Potential threats from long-term discharge:

If this ionized charge is allowed to repeatedly rampage across the porcelain dead end insulators surface, the consequences will be quite serious. The heat and ozone generated by the discharge will continuously corrode the insulating material, making the originally hard surface porous or even carbonized. This damage is irreversible; once a conductive path forms, a complete flashover failure is imminent.